Mobile operators worldwide have launched streaming real-time services (such as mobile TV and radio) over their existing 3G Universal Mobile Telecommunications System (“UMTS”) networks. However, the existing UMTS air-interface and overall network architecture are not adequate to deliver high quality, bandwidth-demanding multimedia content, such as television for a large number of users. Consequently, the 3GPP standards consortium has introduced the Multimedia Broadcasting/Multicasting Service (“MBMS”) framework. The MBMS framework identifies optimizations in the UMTS Radio Access Network (“UTRAN”) and the core network system architecture to enable deployment of multicast/broadcast multimedia applications over the UMTS air-interface and core network.
Because MBMS is intended to serve a large user population, the usage of radio resources must be managed efficiently to avoid system overload due to MBMS services that could degrade the quality of the other services. In conventional MBMS/multimedia streaming, the multimedia traffic is delivered over a single radio access network at a given time. Thus, the delivery is optimized for over-the-air signal combining, where such combining occurs at the lower protocol layers. This configuration still leaves much to be desired in the way of reliability and resolution of multimedia content seen and heard at the user equipment. It would thus be advantageous to improve the perceptual quality of multimedia services delivered over wireless networks.